A personal digital assistant (PDA) is a mobile device that stores information such as a calendar, to-do list, address book, etc. Typically an entry in a PDA's calendar is associated with a date, a starting time, and a duration (or equivalently, ending time), while a task in a to-do list might have an associated priority or an associated due date. A PDA typically has a facility for automatically reminding its user about an upcoming event in the calendar (e.g., the PDA might emit an audible beep ten minutes before a meeting, etc.) In addition, some PDAs (e.g., Microsoft “Pocket-PC” based PDAs, etc.) enable a user to pre-program a reminder for a task in the to-do list, where the user specifies an exact date and time for the reminder to occur.
An emerging trend in consumer electronics is the convergence of PDAs and other devices such as wireless telephones, laptop computers, GPS receivers, digital cameras, MP3 players, etc. For example, combination wireless telephone/PDAs are currently offered by manufacturers such as Samsung and Nokia, and Apple's iPod MP3 players have the capability to store contact and calendar information. Consequently, facilities typically associated with a PDA, including to-do lists, might be offered in other kinds of devices.